The natural language processing module for a voice assisted operator at Telefonica I+D

A natural language processor module has been implemented at Telefonica I+D. This module comprises a semantic parser, a message generator, and a dialog controller which coordinates all the process. The dialog controller is an inference engine that works through a semantic tree. This tree hierarchically organizes the information going from general concepts, towards more specific ones. The dialog strategy at each tree node can be chosen by selecting the node type from among five predefined node types. Output messages are selected by the message generator. There are six different types of messages and two recovery strategies that the message generator can follow. Several output messages for each node in the tree can be defined in order to provide variability. Based on this scheme, a conversational system call ATOS (Automatic Telephone Operator Service) has been designed at Telefonica I+D. We explain the main characteristics of the system and how every module works